1. Field of the Invention
This invention relates to locking devices, and more particularly to improvements in locking devices for detachably locking an engine cover or a seat of a motor car such for example as a cab-over type motor car by means of a turnover mechanism.
2. Description of the Prior Art
As shown in FIG. 1 for example, heretofore a front seat 1 in a cab-over type motor car, not shown generally, has been usually installed on an engine service cover 2. A seat rail, not shown, for this front seat 1 and an anchor 4 of a seatbelt 3 for restraining an occupant is secured to this engine service cover 2. The aforesaid engine service cover 2 is rotatably secured at the rear end thereof to a floor 6 through a hinge 5 so as to be openable upwardly when an engine, not shown, disposed downwardly thereof is subjected to an inspection or the like, and detachably secured at the forward end thereof to the floor 6 through locking devices 7.
The aforesaid locking devices 7 each comprises: a handle 9 rotatably supported on the floor 6 through a support shaft 8; a catch hook 11 rotatably supported by this handle 9 through a rotary shaft 10; and a hook 12 secured to the engine service cover 2 to be fastened to or detached from the floor 6 and engageable with the catch hook 11 at the time of locking. A rotary shaft 10 for rotatably supporting the catch hook 11 on the handle 9 is provided at a position closer to the floor 6 than a straight line passing through the support shaft 8 and a portion of engagement between the catch hook 11 and the hook 12 when the handle 9 approaches the floor 6 to take a locking position, so that the engine service cover 2 can be locked against the floor 6 through the catch hook 11 through a turnover action of the catch hook 11, the action occurring when the handle 9 rotates.
The above-described locking devices 7 of the prior art are disadvantageous in that, when there occurs a relative displacement, which causes the hook 12 to move forward, between the hook 12 and the handle 9 due to an external force such for example as an inertial force, a clamping force by the catch hook 11 is weakened, whereby the handle 9 floats up to a position close to the limit of turnover, so that the engine service cover 2 and the front seat 1 secured thereto float up, thus resulting in an unstable condition.